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Microbial 11α-hydroxylation is one of the most important reactions in the conversion of steroidal C11α-bit in the steroid nucleus and the introduction of an oxygen atom, with a mild reaction conditions, the strong specificity as well as the conversion rate advantages steroidal pharmaceutical industry key production technologies. Rhizopus nigricans (Rhizopus nigricans) is the production of 11 alpha-hydroxy-16a, 17a-epoxy progesterone commonly used strains, the optimum growth temperature of 28 ° C, due to higher summer temperatures, with plenty of cool water to reduce the reaction temperature, caused by high energy consumption, increase the cost of the product, from the strains and transformation of the conditions of its growth and transformation temperature increased. First SW3.41 the investigation of a series of temperature, the temperature rises to 34 ℃, hydroxylation low; In order to improve the ability to transform strain at high temperature substrate, respectively, the strains of single bacteria separation and natural acclimation temperature, at a high temperature in order to further enhance the transforming ability of the strains, and the strain of the a different intensity 60 Co mutagenesis to obtain a strain grown at 34 ° C under a high conversion rate The strain No. SW3.41-11-51. SW3.41-11-51 strain transformed 16 \u0026alpha;, 17a-epoxy progesterone fermentation conditions, by a single prime optimization experiments and orthogonal test to determine the composition of the fermentation medium (g / L): glucose 30, corn steep liquor 30, KH2PO4 2. The optimized culture conditions: initial pH 4.0, fermentation temperature 34 ° C, the liquid volume of 30 mL/250 mL, the rotational speed of 150 r / min, inoculation amount was 10%. In order to improve the microbial cells at a high concentration (12 g / L) for the transforming ability of the bottom object 16a, 17a-epoxy progesterone, its conversion process carried out a series of studies were investigated dissolved oxygen, a dispersing agent, ultrasonic treatment exogenous electron acceptor and organic solvents on the conversion and found that the conversion rate has improved to varying degrees. Wherein the oxygen carrier concentration of the n-dodecane was 5%, the conversion rate compared with the control increased by 39%; dispersant Tween80 concentration of 3%, the conversion rate increased by 62.3% compared with the control; sonicated for aqueous suspensions liquid 10 min conversion rate were increased by 38%; Vitamin K3 exogenous electron acceptor concentration of 5 mg / L conversion rate were increased by 21.1%; A preliminary study on the conversion of organic solvent / water two-phase system to determine the n-dodecane as an oxygen carrier for the organic phase, better conversion effect, were increased by 60% compared with the control. The combination of these optimized conditions, to add the dispersant Tween80 the best conversion rate of 43%, with good prospects for industrial. This is the first study temperature transformation of Rhizopus nigricans bottom material 16a, 17a-epoxy progesterone 11α-hydroxylation reaction kinetics, determination of kinetic parameters Vm and Km 'to 0.034 g / h L and 1.41g / L. Fitting the data obtained with the experimental values of the kinetic equation is consistent.
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